Dresden 2009 – scientific programme

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O: Fachverband Oberflächenphysik

O 24: Methods: Molecular simulations and statistical mechanics

O 24.3: Talk

Tuesday, March 24, 2009, 15:30–15:45, SCH A01

Correlation energy of two-dimensional systems: toward non-empirical and universal modeling — •S. Pittalis^{1, 3}, E. Rasanen^{2, 3}, C. Proetto^{1, 3}, and E.K.U. Gross^{1, 3} — ¹Institut fuer Theoretische Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin, Germany — ²Nanoscience Center, Department of Physics, University of Jyvaskyla, FIN-40014 Jyvaskyla, Finland — ³European Theoretical Spectroscopy Facility (ETSF)

The capability of density-functional theory to deal with the ground-state of correlated systems depends on the accuracy of functionals developed for the exchange and correlation energies. Most of the approximations developed so far have focused on three-dimensional systems. Such efforts for two-dimensional (2D) systems have been relatively scarce despite the rapidly increasing experimental and theoretical interest in 2D structures such as semiconductor heterostructures, quantum-Hall systems, graphene, and various types of quantum dots. Here we derive a correlation-energy functional for 2D systems by modeling the correlation-hole functions in such a way that they satisfy a set of exact properties. We find very encouraging results for a wide range of correlation energies covering several few-electron quantum dots with and without external magnetic field, having different spin-polarizations and current densities.